Back in the Pleistocene thousands of years ago, the pronghorn antelope were prey for the legendary fast cheetahs and hyenas, so they evolved to run fast, really fast. Now that there are no longer cheetahs here in Wyoming, the pronghorn now has the title for fastest land animal in North America running up to 60 mph. Not only do they need space to run, but also since they migrate as well, fences and fragmented developed land are their modern threat. Wyoming has no shortage of space, but they do still have to jump over some fences (literally) to get to greener pastures!